Merge pull request #31380 from frappe/mergify/bp/version-13-hotfix/pr…

…-31372

chore: Fix a potential variable misuse bug (backport #31372)

erpnext/accounts/doctype/pricing_rule/pricing_rule.py

@@ -36,10 +36,15 @@ def validate(self):
 			self.margin_rate_or_amount = 0.0
 
 	def validate_duplicate_apply_on(self):
-		field = apply_on_dict.get(self.apply_on)
-		values = [d.get(frappe.scrub(self.apply_on)) for d in self.get(field) if field]
-		if len(values) != len(set(values)):
-			frappe.throw(_("Duplicate {0} found in the table").format(self.apply_on))
+		if self.apply_on != "Transaction":
+			apply_on_table = apply_on_dict.get(self.apply_on)
+			if not apply_on_table:
+				return
+
+			apply_on_field = frappe.scrub(self.apply_on)
+			values = [d.get(apply_on_field) for d in self.get(apply_on_table) if d.get(apply_on_field)]
+			if len(values) != len(set(values)):
+				frappe.throw(_("Duplicate {0} found in the table").format(self.apply_on))
 
 	def validate_mandatory(self):
 		for apply_on, field in apply_on_dict.items():